CN108405644B - One-way near-solid pressure forming method for tee part blank - Google Patents

Abstract

A method for one-way near-solid pressure forming of a tee part blank belongs to the technical field of tee part blank production and comprises the following steps of ① performing alloy rough smelting and refining on alloy steel at 1600-1700 ℃, ② performing pouring casting on alloy molten steel at 1560 ℃, stirring the alloy molten steel by electromagnetic stirring after pouring, ③ performing demoulding on the cast blank when the solid phase mass percentage of the cast blank reaches 80%, ④ performing surface treatment on the demoulded cast blank, putting the demoulded cast blank into a pressure forming die on a pressurizing device, wherein the temperature of the die and the temperature of a punch are 300 +/-20 ℃, fixing a left punch and a right punch, performing one-way pressurizing on the cast blank through the upper punch, the pressurizing rate of the upper punch is 20-30 mm/s, and the pressurizing time is 2-3 min, ⑤ removing the die after a workpiece is solidified, and taking out a casting blank, namely the pressure forming blank.

Description

One-way near-solid pressure forming method for tee part blank

Technical Field

The invention belongs to the technical field of pressure forming of tee part blanks, and particularly relates to a method for one-way near-solid pressure forming of tee part blanks.

Background

The three-way part is commonly used in industries such as nuclear power, petroleum, chemical engineering, ultra-supercritical thermal power and the like, and the working environment of the three-way part is generally the severe conditions of high temperature, high pressure and easy corrosion, so that the industrial three-way part needs higher strength and organization uniformity. The conventional production methods comprise casting forming, open die forging, multidirectional die forging and the like, wherein the performance of the three-way part formed by casting cannot meet the use requirement easily; the three-way part produced by open die forging has uneven structure performance, long subsequent machining time and low production efficiency; the multi-directional die forging production is to forge the blank in several directions simultaneously or sequentially, so that the mechanical property and the tissue uniformity of the three-way part are improved, but the links of multiple heating, multiple forging and the like of the casting blank exist in the multi-directional die forging processing process, so that the blank of the three-way part is not only easy to generate the defects of oxidation, wrinkling, folding and the like, but also has the defects of energy waste and serious industrial pollution in the process flow.

Disclosure of Invention

The invention aims to provide a method for one-way near-solid pressure forming of a tee part blank, which can effectively overcome the defects in the prior art.

The invention is realized in such a way, and is characterized by comprising the following implementation steps:

1) roughly smelting the alloy steel by adopting an electric arc furnace, and secondarily refining the roughly smelted alloy steel liquid through a vacuum arc remelting furnace at the smelting temperature of 1600-1700 ℃;

2) when the temperature of the alloy steel liquid is reduced to 1560 ℃, pouring the alloy steel liquid into a metal cavity die for centrifugal casting, and after the pouring is finished, carrying out electromagnetic intensive stirring on the alloy steel liquid in the metal cavity die;

3) monitoring the temperature change of the cast blank in the metal cavity die through a thermocouple sensing device, calculating the mass percent of the solid phase of the cast blank, and demolding the cast blank when the mass percent of the solid phase reaches 80%;

4) cleaning the surface of the demolded cast blank, and placing the demolded cast blank into a pressure forming die on a pressurizing device, wherein the temperature of the die and a punch is 300 +/-20 ℃; then fixing the left punch and the right punch, and performing unidirectional pressurization on the cast blank through the upper punch, wherein the pressurization speed of the upper punch is 20-30 mm/s, and the pressurization time is 2-3 min;

5) and after the pressurized workpiece is completely solidified, removing the pressure forming die, and taking out the casting blank to obtain the pressure forming blank.

The alloy steel is heat-resistant alloy steel, high-temperature alloy steel or special alloy steel.

The method has the advantages and positive effects that ① the process is simple, the production efficiency is high, the size precision of the subsequently produced three-way part is high, wrinkles and included angles formed by multiple times of forging are avoided, the performance of the three-way part is improved, ② the production method saves the heating process of multiple times of forging, reduces the investment of equipment and manpower, and meets the green production requirements of energy conservation and emission reduction.

Drawings

FIG. 1 is a cross-sectional view of a cast billet;

FIG. 2 is a left side view of FIG. 1;

FIG. 3 is a top view of FIG. 1;

FIG. 4 is a cross-sectional view of a one-way press formed blank;

FIG. 5 is a schematic view of a one-way press forming die;

FIG. 6 is a left side view of FIG. 5;

in the figure:

1-upper punch; 2-core rod; 3-right punch; 4-pressure forming the blank; 5-lower die; 6-left punch; 7-upper die; s-vertical hole; z-left hole; y-right hole; p-applied pressure.

Detailed Description

The present invention will be described in further detail with reference to examples

Example 1

Producing a one-way press-formed blank of AISI-5140 alloy steel, structured as shown in figure 4, wherein the embodiment is as follows:

1) heating AISI-5140 alloy steel to 1600 ℃ by adopting an electric arc furnace for rough smelting, and then carrying out secondary refining on the alloy molten steel after the rough smelting through a vacuum arc remelting furnace, wherein the refining temperature is 1650 ℃;

2) when the temperature of the alloy steel liquid is reduced to 1560 ℃, pouring the alloy steel liquid into a metal cavity die for centrifugal casting, and after the pouring is finished, carrying out electromagnetic intensive stirring on the alloy steel liquid in the metal cavity die;

3) monitoring the temperature change of the cast blank in the metal cavity die through a thermocouple sensing device, calculating the mass percent of the solid phase of the cast blank, and demolding the cast blank when the mass percent of the solid phase reaches 80%;

4) cleaning the surface of the demolded cast blank, and placing the demolded cast blank into a pressure forming die on a pressurizing device shown in fig. 5, wherein the temperature of an upper die 7, a lower die 5, a core rod 2, an upper punch 1, a right punch 3 and a left punch 6 is 300 +/-20 ℃; then fixing the left punch 6 and the right punch 3, and performing unidirectional pressurization on the casting blank through the upper punch 1, wherein the pressurization speed of the upper punch 1 is 20-30 mm/s, and the pressurization time is 3 min;

5) and after the pressurized workpiece is completely solidified, removing the pressure forming die, and taking out the casting blank to obtain the pressure forming blank.

Example 2

Producing a unidirectional pressure formed blank of AISI-1045 alloy steel, structured as shown in figure 4, wherein the embodiment is as follows:

1) heating AISI-1045 alloy steel to 1600 ℃ by adopting an electric arc furnace for rough smelting, and then carrying out secondary refining on the roughly smelted alloy steel liquid through a vacuum arc remelting furnace, wherein the refining temperature is 1650 ℃;

2) when the temperature of the alloy steel liquid is reduced to 1560 ℃, pouring the alloy steel liquid into a metal cavity die for centrifugal casting, and after pouring is finished, carrying out electromagnetic intensive stirring on the alloy steel in the metal cavity die;

3) monitoring the temperature change of the cast blank in the metal cavity die through a thermocouple sensing device, calculating the mass percent of the solid phase of the cast blank, and demolding the cast blank when the mass percent of the solid phase reaches 80%;

4) cleaning the surface of the demolded cast blank, and placing the demolded cast blank into a pressure forming die on a pressurizing device shown in fig. 5, wherein the temperature of an upper die 7, a lower die 5, a core rod 2, an upper punch 1, a right punch 3 and a left punch 6 is 300 +/-20 ℃; then fixing the left punch 6 and the right punch 3, and performing unidirectional pressurization on the casting blank through the upper punch 1, wherein the pressurization speed of the upper punch 1 is 20-30 mm/s, and the pressurization time is 3 min;

5) and after the pressurized workpiece is completely solidified, removing the pressure forming die, and taking out the casting blank to obtain the pressure forming blank.

Claims (2)

1. A method for one-way near-solid pressure forming of a tee part blank is characterized by comprising the following steps:

1) roughly smelting alloy steel by adopting an electric arc furnace, and secondarily refining the roughly smelted alloy steel liquid through a vacuum arc remelting furnace at the smelting temperature of 1600-1700 ℃;

2) when the temperature of the alloy steel liquid is reduced to 1560 ℃, pouring the alloy steel liquid into a metal cavity die for centrifugal casting, and after the pouring is finished, carrying out electromagnetic intensive stirring on the alloy steel liquid in the metal cavity die;

3) monitoring the temperature change of the cast blank in the metal cavity die through a thermocouple sensing device, calculating the mass percent of the solid phase of the cast blank, and demolding the cast blank when the mass percent of the solid phase reaches 80%;

4) cleaning the surface of the cast blank after demolding, and placing the cast blank into a pressure forming die on a pressurizing device, wherein the temperature of the die and a punch is 300 +/-20 ℃; fixing the left punch head (6) and the right punch head (3), and performing unidirectional pressurization on the cast blank through the upper punch head (1), wherein the pressurization speed of the upper punch head (1) is 20-30 mm/s, and the pressurization time is 2-3 min;

5) and after the pressurized workpiece is completely solidified, removing the pressure forming die, and taking out the casting blank to obtain the pressure forming blank.

2. The method for unidirectional near-solid pressure forming of a three-way part blank according to claim 1, wherein: the alloy steel is heat-resistant alloy steel, high-temperature alloy steel or special alloy steel.

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